Surveillance cameras caught the disturbing crime on video when in took place in May of 2012. Prosecutors showed the graphic recording to jurors during Matthew Johnson’s capital murder trial Monday.

Matthew Lee Johnson, 36, is accused of setting a store clerk on fire during a robbery. (Credit: Garland PD)

The video showed Johnson entering the convenience store, then he quickly goes behind the counter and forces Harris to open the register and give him money. Off camera, Johnson doused Harris with lighter fluid, and then set her on fire. In the video he is seen nonchalantly walking out of the store.

Harris had already pressed the panic button and police were on the way. She is seen walking around the convenience store in flames. She walks out of the store to wait for police. An officer is seen using a fire extinguisher to put out the flames.

Firefighter Gary Church testified Harris had 1st, 2nd, and 3rd degree burns on her face, shoulders, abdomen, arms and legs.

“She was in a lot of pain. She was very worried. The only thing she said at the time was, ‘Help me! Help me!’ and said she was in a lot of pain,” he testified.

Later, a neighbor, who wished to remain anonymous, testified Johnson tried to force his way into his home, asking for help, a short time after the crime. “His eyes were real wide and big and he was fighting for no apparant reason other than to try to get into my house,” the neighbor said.

Garland police Officer Billey Coffey took the stand and said Johnson repeatedly tried to engage him in conversation.

The day ended with more testimony from investigators who collected evidence from the scene, including the water bottle filled with lighter fluid police say Johnson used to douse Harris before setting her afire.